Rotatable fastener having circular toothed tool receiving groove



Nov. 19, 1957 2513,450

w. o zus ROTATABLE FASTENER HAVING c CULAR TOO'I'HED TOOL RECEiVI-NG c VE 4 Filed May :5, 1954 lNVENTO R 2,813,450 nornrnnrn rasrmsnirsvme emouLAR TOOTHEDTQQLREEEWINGGROOVE WilliamDzus, West- IslipgN. Y V Application May a, 1954, Serial No. 427,161 5 1 Claim. e1. 8545) invention relates toanimproved rotatable fasten- Un ta s; Patent ing' 'device and more particularly to an improved operating head portion for receiving a tool to cause the rotation of the fastening device. a

Devices such as screws, bolts and nuts are frequently provided with slots, kerfs, recesses or sockets for receiving tools such as screw drivers or wrenches whereby the fastening device may be readily rotated to close or open it. The slots, sockets and recesses heretofore available have had recognized disadvantages. Thus, they were so designed that they would be readily mutilated by the tool or the tool could become disengaged therefrom under excessive torque. That the difficulties have persisted is indicated by the innumerable variations that have been suggested in the design of the slots, sockets or recesses.

It is an object of the present invention to overcome the difiiculties heretofore encountered and to provide an improved tool-receiving operating head for a rotatable fastening device which will not be mutilated by the tool and which is so designed that the tool will not become disengaged therefrom even under excessive torque.

Further objects are the provision of an improved operating head of the above character which is readily applicable to various types of rotatable fastening devices and which is of improved, simplified design so that it can be used even by inexperienced operators and will give satisfactory service over a long period of time with a minimum amount of wear.

Another object is the provision of an improved tool to be used in operating rotary types of fastening devices and embodying the several advantages as set forth above in connection with the operating head.

In the accompanying drawing:

Fig. l is a top plan view of the operating head of a rotatable fastening device embodying my invention;

Fig. 2 is a fragmentary elevational view showing the operating head of the fastening device, together with the lower portion of the operating tool about to be applied thereto;

Fig. 3 is a partially sectional, partially fragmentary view in the direction of the arrows on the line 33 of Fig. 1 showing the tool applied to the operating head so as to cause the rotation thereof.

Fig. 4 is a cross-sectional view in the direction of the arrows on the line 44 of Fig. 3 showing the tool applied to the head and indicating the relative position of the parts when the tool is utilized to rotate the fastening device in a clockwise direction, as shown by the arrow; and

Fig. 5 is a similar view to Fig. 4 but showing the relative positions of the parts when the tool is utilized to rotate the fastening device in a counter-clockwise direction, as shown by the arrow.

My invention is applicable to any rotary type of fastening device and, in the accompanying drawing, is shown as applied to the upper end of a rotatable fastener stud 10.

The fastener stud is provided with an operating head 11 having an improved form of tool-receiving ring formed therein- The ring extends around the central axis of the stud and is positioned in a plane oifset with respect to the plane ofthe surface of the head. Thus, the. ring preferablydakes the. form of; a: groove 12.. Atleastione-,,preferably both as shown, of, the peripheral edges of the groove, are. formed with serrations, teeth. or notches indicatedlatfi for the. outer peripheral. edge and 14 for the inner peripheral edge. The,v notches are designed. to receivesimilarily shaped teeth formedon the operating tool so. arotar-y motion of the tool. will, in turn, be imparted. to,- the fastening device. The teeth or notches are so formed thatv at least one edge or wall. of each, notch extendsin a generally radialdirection, and; the radial Walls ofrtheunutches. formed. in one peripheral edge. face. in onedirection while the, radial. walls of the notches formed inthe other: peripheral: edge face in the opposite direction. Thus, itwill, be seen that the radial walls of the, matches lfik facel, in. a. clockwise direction. while. the radial. walls of, the notches 1.4 face in a. counterclockwise direction.

suitable tool, suchas. that v shown, in, Figs. 2 to 5, is provided for engagement with the ring-shaped groove to cause rotation of the fastening device. Thus, the tool may have a tubular shank 15 having a suitable operating handle 16. The lower portion of the tool has a ringshaped operating part 17 of a size and shape to engage with the serrated ring-shaped groove 12. Thus, the ringshaped operating part of the tool has outwardly projecting teeth each with a radial wall facing in a clockwise direction and also inwardly projecting teeth each with a radial wall projecting in a counter-clockwise direction. The ring and teeth correspond in size and shape with the serrated groove and engage therewith in snug relationship, as shown in Figs. 3, 4, and 5.

When the tool is rotated in a clockwise direction, the radial walls of the outwardly projecting teeth of the tool engage with the radial walls of the outwardly projecting notches of the fastening device, as shown in Fig. 4. Simultaneously the angularly disposed walls of the inwardly projecting teeth of the tool engage the angularly disposed surfaces of the inwardly projecting notches of the fastening device. This firm interengagement prevents slippage and mutilation and provides adequate contact surface for even excessive torque loads. When the tool is rotated in a counterclockwise direction, the radial walls of the inwardly projecting teeth of the tool engage the radial walls of the inwardly projecting notches of the fastening devices, while, simultaneously, the angularly disposed walls of the outwardly projecting teeth of the tool engage the angularly disposed walls of the outwardly projecting notches of the fastening device. This also insures firm interengagement preventing slippage and mutilation and provides adequate surface contact area to withstand even excessive torque loads.

It will be seen that the tool can be readily applied to the head by placing the ring-shaped end in registry with the groove and then rotating it until the notches and teeth are in alignment with each other. The tool can be separated from the head by a simple axial movement. When the parts are in engagement with each other, there is no danger of slippage or mutilation due to the positive engagement of the teeth and notches as explained above. My improved arrangement provides considerably more contact surface between the tool and the fastening device. This is advantageous in preventing mutilation, slippage and disengagement. This, of course, is particularly advantageous in the case of fastening devices having relatively thin operating heads.

My invention is applicable to any rotatable fastening divice such as a screw, bolt, quick-acting fastener or the li c.

It will be appreciated that modifications may be made in the illustrated and described embodiment of my invention without departing from the invention as set forth in the accompanying claim. Thus, the ring may be embossed upon the surface of the head and the tool may be formed with a grooved ring for receiving the embossed ring.

I claim:

In a rotatable fastening device of the type which is operated by rotating it around its central axis, the improvement which comprises a head portion at one end of the fastening device and having a tool engaging upper surface, said surface being formed with a tool receiving continuous ring shaped groove extending around the iongitudinal axis of the device with the open face of the groove facing upwardly in the direction of the longitudinal axis of the device, said groove having radially spaced side walls parallel to the longitudinal axis, each of said side walls being formed with a plurality of tooth shaped projections projecting into the groove from the opposite sides thereof, one wall of each tooth being substantially radial and the other wall of each tooth being inclined at an angle to the radial wall and extending from the top of the tooth substantially to the base of the radial wall of the next succeeding tooth With the substantially radial walls of the teeth formed on one side wall of the groove being arranged to face in a clockwise direction of rotation and with the substantially radial walls of the teeth formed on the other side wall of the groove being arranged to face in a counterclockwise direction of rotation and also all of said radial walls being arranged so that extensions thereof would intersect the central longitudinal axis of rotation of the fastening device.

References Cited in the file of this patent UNITED STATES PATENTS Re. 22,681 Bugg Oct. 16, 1945 755,804 Smith ....7 Mar. 29, 1904 874,543 Scheuer Dec. 24, 1907 2,083,092 Richer June 8, 1937 2,362,999 Hewitt Nov. 21, 1944 2,375,249 Richer May 8, 1945 2,518,886 Halvorsen Aug. 15, 1950 2,538,468 North Jan. 16, 1951 2,735,325 Rudd Feb. 21, 1956 FOREIGN PATENTS 13,555 Great Britain June 11, 1913 156,457 Germany July 10, 1939 

